Elastic anomalies of YbIrGe in magnetic fields

International Conference on Strongly Correlated Electron Systems 2014

Suzuki, T.^1,2,3 ; Noguchi, Y.^1 ; Ishii, I.^1 ; Goto, H.^1 ; Kamikawa, S.^1 ; Fujita, T.K.^1 ; Katoh, K.^4

Department of Quantum Matter, ADSM, Hiroshima University, Higashi-Hiroshima, Hiroshima

739-8530, Japan^1

Institute for Advanced Materials Research, Hiroshima University, Higashi-Hiroshima, Hiroshima

739-8530, Japan^2

Cryogenics and Instrumental Analysis Division, N-BARD, Hiroshima University, Higashi-Hiroshima, Hiroshima

739-8526, Japan^3

Department of Applied Physics, National Defense Academy, Kanagawa, Yokosuka

239-8686, Japan^4

关键词: Antiferromagnetic orderings;    Crystal electric field;    Crystal electric field effect;    Heavy fermion compounds;    Orthorhombic structures;    Quadrupole interactions;    Temperature dependence;    Zero magnetic fields;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/592/1/012018/pdf
DOI  :  10.1088/1742-6596/592/1/012018

来源: IOP

【 摘 要 】

The Yb-based heavy-fermion compound YbIrGe, which has the orthorhombic structure, shows the crystal electric field effect at high temperatures and antiferromagnetic orderings at TN=2.4 K and Tm=1.4 K. We previously found anomalous elastic softening in zero magnetic field originating from an indirect quadrupole interaction between the ground doublet and the excited doublets, and determined the crystal electric field level scheme: the ground doublet and an excited doublet at 138 K. To investigate the antiferromagnetic orderings at TNand Tm, we performed ultrasonic measurements under magnetic fields along the a-axis on YbIrGe single crystals. Temperature dependence of elastic modulus C11exhibits elastic hardening below both TNand Tmat 0 T. As increasing the magnetic field along the a-axis, both TNand Tmdecrease monotonically, suggesting that both transitions are antiferromagnetic ordering. TNcloses around 2 T, and Tmdisappears above 1 T. We clarified the magnetic field- temperature phase diagram along the a-axis.